The magnetic-recording, hard-disk-drive (HDD) industry is extremely competitive. The demands of the market for ever increasing storage capacity, as bench-marked by areal density, create tremendous pressure for achieving technological advancements. Therefore, procedures that can lead to greater understanding of the magnetic-recording process in advanced HDD technology attract significant attention on the part of engineers and scientists engaged in the design of these complex devices.
With the arrival of ultra-high-density (UHD), magnetic-recording technology, the desire for understanding the magnetic-recording process has gained even greater importance. In particular, perpendicular-magnetic-recording (PMR) heads used in UHD HDDs have attracted significant attention from the HDD engineering community, because the write characteristics of PMR heads can have a significant impact on the track density, as measured in tracks per inch (tpi), as data tracks are packed ever closer together in UHD HDDs. Thus, greater understanding of the write characteristics of PMR heads and disks that affect areal density in UHD HDDs is of paramount importance.